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Institute for Theoretical Chemistry (T3.0)
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von Szentpály

László von Szentpály

Dr.

Senior Scientist (retired)
Institute for Theoretical Chemistry
Institute for Theoretical Chemistry

Contact

+49 711 685 64408
+49 711 685 64442
Email

Pfaffenwaldring 55
70569 Stuttgart
Deutschland
Room: 8.106

Publications

Publications of Laszlo v. Szentpaly:

2020
1. von Szentpály, L. (2020). Theorems and rules connecting bond energy and bond order with electronegativity equalization and hardness maximization. Theoretical Chemistry Accounts, 139 (3), 54.
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  @article{vonSzentpály2020, abstract = {Bond orders are attributed a new role in rationalizing the electronegativity equalization (ENE) and maximum hardness (MH) rules. The following rules and theorems are formulated for chemical species (atoms, groups, molecules), X, Y, XY, their ionization energies, I, electron affinities, A, electronegativity, kh = {\oe}(I + A), and chemical hardness, e = {\oe} (I - A). Rule 1 Sanderson's principle of electronegativity equalization is supported (individual deviations < 10\%) by association reactions, X + Y - XY, if the ionic bond dissociation energies are equal, D (XY+) = D (XY-), or, equivalently, if the relative bond orders are equal, BOrel (XY+) = BOrel (XY-). Rule 2 Sanderson's principle of electronegativity equalization is supported (individual deviations < 10\%) by association reactions, X + Y - XY, if the formal bond orders, FBO, of the ions are equal, FBO (XY+) = FBO (XY-). Theorem 1 The electronegativity is not equalized by association reactions, X + Y - XY, if the formal bond orders of the ions differ, FBO (XY+) - FBO (XY-) ［?］ 0. Theorem 2 The chemical hardness is increased by nonpolar bond formation, 2X - X2, if (and for atomic X: if and only if) the sum BOrel (X2+) + BOrel (X2-) < 2. Rule 3 The chemical hardness is decreased, thus the "maximum hardness principle" violated by association reactions, X + Y - XY, if (but not only if) BOrel (XY+) + BOrel (XY-) > 2. The theorems are proved, and the rules corroborated with the help of elementary thermochemical cycles according to the first law of thermodynamics. They place new conditions on the "structural principles" ENE and MH. The performances of different electronegativities and hardness scales are compared with respect to ENE and MH. The scales based on valence-state energies perform consistently better than scales based on ground-state energies. The present work provides the explanation for the order of magnitude better performance of valence-state ENE compared to that of the ground-state ENE. We here show by a new approach that the combination of several fuzzy concepts clarifies the situation and helps in defining the range of validity of rules and principles derived from such concepts.}, author = {von Szentp{\'a}ly, L{\'a}szl{\'o}}, doi = {10.1007/s00214-020-2569-0}, issn = {1432-2234}, journal = {Theoretical Chemistry Accounts}, number = 3, pages = 54, title = {Theorems and rules connecting bond energy and bond order with electronegativity equalization and hardness maximization}, url = {http://dx.doi.org/10.1007/s00214-020-2569-0}, volume = 139, year = 2020 }
  Link
  http://dx.doi.org/10.1007/s00214-020-2569-0
2019
1. von Szentpály, L., Schwarz, W. H. E., Stoll, H., & Werner, H.-J. (2019). Correspondence on “Core Electron Topologies in Chemical Compounds: Case Study of Carbon versus Silicon.” Angewandte Chemie International Edition, 58, 2–6.
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  @article{doi:10.1002/anie.201812959, abstract = {Abstract The conclusions of a recent Communication of Yoshida, Raebiger, Shudo, and Ohno published in this journal, that varying core orbital topologies with minuscule negative tails upon bond formation determine the different chemistries of carbon and silicon and affect ionization energies, excitation energies and bond properties of molecules, are now shown to be based on computational artifacts and oversimplified models. The all-electron wave function uniquely determines the observables, while its representation by one-electron orbital products depends on the details of the chosen approximation and therefore need to be considered with great care.}, author = {von Szentpály, László and Schwarz, W. H. Eugen and Stoll, Hermann and Werner, Hans-Joachim}, doi = {10.1002/anie.201812959}, eprint = {https://onlinelibrary.wiley.com/doi/pdf/10.1002/anie.201812959}, journal = {Angewandte Chemie International Edition}, pages = {2-6}, title = {Correspondence on “Core Electron Topologies in Chemical Compounds: Case Study of Carbon versus Silicon”}, url = {https://doi.org/10.1002/anie.201812959}, volume = 58, year = 2019 }
  Link
  https://doi.org/10.1002/anie.201812959
2018
1. von Szentpály, L. (2018). Multiply Charged Anions, Maximum Charge Acceptance, and Higher Electron Affinities of Molecules, Superatoms, and Clusters. Acta Physico-Chimica Sinica, 34 (6), 675.
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  @article{Szentpaly;LY:675, author = {von Szentpály, László}, doi = {10.3866/PKU.WHXB201801021}, eid = {675}, journal = {Acta Physico-Chimica Sinica}, number = 6, numpages = {7}, pages = 675, publisher = {Acta Phys. -Chim. Sin.}, title = {Multiply Charged Anions, Maximum Charge Acceptance, and Higher Electron Affinities of Molecules, Superatoms, and Clusters}, url = {http://www.whxb.pku.edu.cn/EN/abstract/article_30139.shtml}, volume = 34, year = 2018 }
  Link
  http://www.whxb.pku.edu.cn/EN/abstract/article_30139.shtml
2. Szentpály, L. von. (2018). Eliminating symmetry problems in electronegativity equalization and correcting self‐interaction errors in conceptual DFT.
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  @misc{dftlvonszentply2018eliminating, author = {Szentpály, László von}, doi = {10.1002/jcc.25356}, note = {interaction errors in conceptual}, title = {Eliminating symmetry problems in electronegativity equalization and correcting self‐interaction errors in conceptual DFT}, url = {https://www.doi.org/10.1002/jcc.25356}, year = 2018 }
  Link
  https://www.doi.org/10.1002/jcc.25356
2017
1. von Szentpály, L. (2017). Hardness maximization or equalization? New insights and quantitative relations between hardness increase and bond dissociation energy. Journal of Molecular Modeling, 23 (7), 217.
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  @article{vonSzentpály2017, abstract = {It has been overlooked that the change of hardness, $\eta$, upon bonding is intimately connected to thermochemical cycles, which determine whether hardness is increased according to Pearson's ``maximum hardness principle'' (MHP) or equalized, as expected by Datta's ``hardness equalization principle'' (HEP). So far the performances of these likely incompatible ``structural principles'' have not been compared. Computational validations have been inconclusive because the hardness values and even their qualitative trends change drastically and unsystematically at different levels of theory. Here I elucidate the physical basis of both rules, and shed new light on them from an elementary experimental source. The difference, $\Delta$$\eta$ = $\eta$mol -- <$\eta$at>, of the molecular hardness, $\eta$mol, and the averaged atomic hardness, <$\eta$at>, is determined by thermochemical cycles involving the bond dissociation energies D of the molecule, D+ of its cation, and D− of its anion. Whether the hardness is increased, equalized or even reduced is strongly influenced by $\Delta$D = 2D -- D+ − D−. Quantitative expressions for $\Delta$$\eta$ are obtained, and the principles are tested on 90 molecules and the association reactions forming them. The Wigner-Witmer symmetry constraints on bonding require the valence state (VS) hardness, $\eta$VS, instead of the conventional ground state (GS) hardness, $\eta$GS. Many intriguingly ``unpredictable'' failures and systematic shortcomings of said ``principles'' are understood and overcome for the first time, including failures involving exotic and/or challenging molecules, such as Be2, B2, O3, and transition metal compounds. New linear relationships are discovered between the MHP hardness increase $\Delta$$\eta$VS and the intrinsic bond dissociation energy Di. For bond formations, MHP and HEP are not compatible, and HEP does not qualify as an ordering rule.}, author = {von Szentpály, László}, day = 01, doi = {10.1007/s00894-017-3383-z}, issn = {0948-5023}, journal = {Journal of Molecular Modeling}, month = {07}, number = 7, pages = 217, title = {Hardness maximization or equalization? New insights and quantitative relations between hardness increase and bond dissociation energy}, url = {https://doi.org/10.1007/s00894-017-3383-z}, volume = 23, year = 2017 }
  Link
  https://doi.org/10.1007/s00894-017-3383-z
2016
1. von Szentpály, L. (2016). Comment on “A new equation based on ionization energies and electron affinities of atoms for calculating of group electronegativity” by S. Kaya and C. Kaya Comput. Theoret. Chem. 1052 (2015) 42–46. Computational and Theoretical Chemistry, 1083, 72–74.
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  @article{VONSZENTPALY201672, abstract = {Kaya and Kaya’s equation for calculating group electronegativity by global equalization of atomic electronegativities is neither new, nor reliable. Critical comments are presented concerning: (i) the dramatic failure of global ground-state electronegativity equalization (ENE) and the reasons thereof, (ii) the importance of the Wigner–Witmer symmetry laws to obtain accurate ENE in localized bonds, (iii) the electron self-interaction error causing unreasonably small partial charges, (iv) the fact that the “new equation” and global ENE generally yield identical partial charges on all atoms-in-the-molecule of the same element independent of their neighbors, (v) the electron donating power of alkyl groups. Tools and models to correct for the failures and improve the accuracy of local ENE and the resulting partial atomic charges are indicated.}, author = {von Szentpály, László}, doi = {https://doi.org/10.1016/j.comptc.2016.02.008}, issn = {2210-271X}, journal = {Computational and Theoretical Chemistry}, pages = {72 - 74}, title = {Comment on “A new equation based on ionization energies and electron affinities of atoms for calculating of group electronegativity” by S. Kaya and C. Kaya [Comput. Theoret. Chem. 1052 (2015) 42–46]}, url = {http://www.sciencedirect.com/science/article/pii/S2210271X16300305}, volume = 1083, year = 2016 }
  Link
  http://www.sciencedirect.com/science/article/pii/S2210271X16300305
2015
1. von Szentpály, L. (2015). Symmetry Laws Improve Electronegativity Equalization by Orders of Magnitude and Call for a Paradigm Shift in Conceptual Density Functional Theory. The Journal of Physical Chemistry A, 119 (9), 1715–1722.
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  @article{doi:10.1021/jp5084345, author = {von Szentpály, László}, doi = {10.1021/jp5084345}, eprint = {https://doi.org/10.1021/jp5084345}, journal = {The Journal of Physical Chemistry A}, note = {PMID: 25333372}, number = 9, pages = {1715-1722}, title = {Symmetry Laws Improve Electronegativity Equalization by Orders of Magnitude and Call for a Paradigm Shift in Conceptual Density Functional Theory}, url = {https://doi.org/10.1021/jp5084345}, volume = 119, year = 2015 }
  Link
  https://doi.org/10.1021/jp5084345
2. von Szentpály, L. (2015). Physical Basis and Limitations of Equalization Rules and Principles: Valence-State Electronegativity and Valence-Pair-Affinity versus Operational Chemical Potential. Quantum Matter, 4 (1), 47–55.
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  @article{Szentpaly_2015_47, abstract = {The postulated identity of the operational chemical potential, , with the negative of the ground-state electronegativity, = X GS, is a cornerstone of conceptual DFT (cDFT). However, a trend has developed to overestimate the applicability and accuracy of the corresponding equalization principles. The operational molecular mol in general does not result from equalizing atomic at values. Frequent violations of the strict Wigner-Witmer symmetry rules by cDFT cause mol at in homonuclear diatoms. Consequently the previous general proofs of the chemical potential equalization (CPE) principle and its equivalence to the electronegativity equalization (ENE) principle seem inadequate. Such fundamental limitations of cDFT need to be addressed, and solutions proposed also in connection with violations of the variational principle due to electron-self-interaction errors. Mulliken's valence-state definition of electronegativity, VS, intrinsically fulfils the Wigner-Witmer rules, and ENE by VS is surprisingly accurate for homonuclear diatoms. For polar bonds a charge dependent generalization of Mulliken's VS is introduced as Valence-Pair-Affinity, VPA. It is consistently derived from Ruedenberg's theory of the chemical bond and does neither violate the variational principle nor the Wigner-Witmer rules. VPA is locally equilibrated in 2-center electron-pair bonds, but not in the whole molecule. The partial atomic charges obtained by VPA equilibration are consistent and agree well with those obtained by Natural Bond Orbital population analysis and the ones found in Klopman's equipotential orbitals.}, author = {von Szentpály, László}, doi = {doi:10.1166/qm.2015.1170}, eissn = {2164-7623}, issn = {2164-7615}, itemtype = {ARTICLE}, journal = {Quantum Matter}, keyword = {PARTIAL CHARGE, MULLIKEN VALENCE STATE, CHEMICAL POTENTIAL, RUEDENBERG VALENCE STATE, VALENCE-PAIR-AFFINITY, EQUALIZATION PRINCIPLES, WIGNER-WITMER SYMMETRY RULES, BOND POLARITY, ELECTRONEGATIVITY EQUALIZATION, CONCEPTUAL DFT}, number = 1, pages = {47-55}, parent_itemid = {infobike://asp/qm}, publishercode = {asp}, title = {Physical Basis and Limitations of Equalization Rules and Principles: Valence-State Electronegativity and Valence-Pair-Affinity versus Operational Chemical Potential}, url = {https://www.ingentaconnect.com/content/asp/qm/2015/00000004/00000001/art00004}, volume = 4, year = 2015 }
  Link
  https://www.ingentaconnect.com/content/asp/qm/2015/00000004/00000001/art00004

Publications before 2015

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Theorems and rules connecting bond energy and bond order with electronegativity equalization and hardness maximization

László von Szentpály

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2020

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2019

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2018

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2017

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2016

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2020

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2019

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2018

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2017

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2016

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